Bicycle frame



FIG. 1 is a perspective view of a bicycle frame showing our new design;

FIG. 2 is a right side elevational view thereof, the undisclosed left side being a mirror image;

FIG. 3 is a right side elevational view thereof, the broken lines shown are for illustrative purposes only and form no part of the claimed design;

FIG. 4 is a rear elevational view thereof;

FIG. 5 is a front elevational view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof. 

The ornamental design for a bicycle frame, as shown and described. 